BLOCK Islanders have a name for the land to the west, 10 miles across the Sound where civilization grunts and snarls. They call it "America."

You needn't stay long on the island, or any small island, to see why the locals feel different.

Islanders ignore the speed limit. They drive slower. They do it because there's nowhere to go but around the loop, so why hurry if you're going to end up where you started? And they do it because around every bend there is another sweeping look at something soothing.

Locking things up is a waste of island time because if someone stole your stuff eventually you'd see him with it, or the whole town could watch him load it on the ferry.

Island life thus short-circuits two mainland constants, speed and fear. How un-American can you get?

Leave the island and it's as if someone threw you into a high-volume, trash-processing machine-the whistle of Lincoln Town Cars slashing down Rte. 95, glassy-eyed drivers locked in air-conditioned, stereophonic torpor; the rattling thunder of dirty trucks.

We're in Bethany this summer, our first vacation in years on anything but an island. There is a horror two blocks away, Rte. 1, another 10 miles away, Ocean City, and a mystery in the downstairs half of the duplex--a family from Indiana.

Yesterday we came home with a nice little mess of fish from the ocean. "What'd you get?" asked an Indianan.

"Some flounders," said I, "two bluefish and a sea trout." He looked puzzled. "Oh, yeah," I said, "and a coupla small sharks."

I might as well have hollered "fire." The downstairs of the duplex exploded. They came running, screaming, "Shark! He caught a shark! Where's the shark?"

That night, lying in bed, I asked my wife what it was about islands. "Simple," she said. "Everybody can't get there."

Because of shoals surrounding them, practically no one can get to the uninhabited marsh islands of the Chesapeake. Even if they could, few would. Think of the phrase, "tropical French penal colony." That's what these islands are like in slack-still summer, when people take vacations.

Some lawyers recently bought Poplar and Jefferson, adjoining Bay islands that presidents Franklin D. Roosevelt and Harry Truman used to repair to for recreation.

One of the new owners led a foray to Jefferson on a muggy June day. You might as well have been in hell. It was low ground, ripe with chiggers, ticks, mosquitoes, poison ivy, snakes and a searing, wet heat.

Holland Island down the Bay was for sale, too. Manuel Munoz-Carrasco, a duck hunter, went exploring to see if it was worth our bidding on. Holland was listed as 190 acres, but the real estate man said he "wouldn't swear to any more than 100," because of the way it was eroding.

They can keep their 100. Even Munoz, like all waterfowlers impervious to physical discomfort, was driven out by the massed mosquitoes and the 102-degree, breezeless July heat.

Ahh, but come back in October or November. Or to nearby Bloodsworth, South Marsh or the uninhabited marshes between Smith and Tangier, or to the high woods of Watts, where roosters still crow and goats roam, remnants of the days when it was farmed. In fall you'll see something.

We ran a hunting trip one October to the marsh between Smith and Tangier, camping on the beach at a tidal gut.

On breezy days we'd set out before dawn to hunt pintails, widgeons, black ducks and mallards. On still days we'd take the boat into Tangier Sound and catch spots, croakers and blues.

One morning a marsh hawk dove and captured a sparrow at the very feet of Munoz, who watched, unseen, amazed.

Somewhere someone has a piece of paper that says he owns that island campsite and the land around it, but there was no sign humans had been there ever. It was as wild a place as I've been, ours for the taking when we chose, and for the ignoring on those miserable days it was uninhabitable.

We should have decided then that the islands of the Chesapeake were for visiting, not owning. Let someone else fight the chiggers. Let someone else's heart break when the land washes away.

The business of owning an island or a piece of an island is a hoax. A mainland mentality leads the course from "I like it" to "I want it" to "I will buy it."

If you like islands, as I do perhaps more than is healthy, don't buy one, or even a little house on one. Buy a boat instead. Then every island is yours. This is the pirate mentality, which leads the merry course from "I like it" to "I want it" to "I will TAKE it."

It's a sense of self-dependency that sets apart the islandman, as Irishman Tomas O'Crohan called himself. I recall it from the first time I stepped on a low-tide sandbar off Long Island to clam as an 8-year-old.

"This is my island," I thought, "until the tide takes it away." I felt that my fate, for the first time, was utterly mine. If the boat were anchored poorly and drifted away, it was my neck at high tide.

Thirty years and hundreds of landfalls later I have yet to gain a small island without a feeling of achievement and anticipation. Will it storm? Will we be marooned? Will the boat run or the ferries operate when it's time to go back? Will we find the mussels and clams and oysters and crabs? Will the big fish hit the coves and points? What time is high tide? Where shall we anchor? Could the Bay freeze, as it did on South Marsh Island one January when we had to break ice in little boats to regain the mainland? Will fog swallow us? Have we brought the right tools, enough food?

The small-island resident, no matter how short his stay or summer-populated his place, faces certain tasks the mainlander doesn't. There may be no mechanic to fix his machines; no doctor to fix his wounds. Like the good boatman, he will at one time or another be carpenter, mechanic, doctor, judge of danger, farmer, fisherman, weatherman, scientist.

The pleasantest islands in the east lie between Long Island and Cape Cod, but as a consequence of their choice location and character they are overpopulated in tourist season. Nonetheless Block Island, Martha's Vineyard, Nantucket, Cuttyhunk and the other small islands in the Elizabeth Chain are worth visiting

One morning at red dawn off Nantucket in June the stripers came like bulldozers, rolling through the feathery tide rip. Four of us were aboard. We all cast lures at once and all hooked up. Ten furious minutes later 110 pounds of striped bass was in the catchbox. What wealth!

In Casco Bay off Maine the islands are rocky and multitudinous. Many are unpopulated. Leave the boat and walk the woods of birch and pine, but don't stay too long or the tide will fall out and leave you high and dry. It's six hours of falling and six hours of rising before you're afloat. I've counted the hours, chagrined, the skiff beached and careened, a pile of clams at my feet, food for the wait.

Our interest in Holland Island was sparked by satisfying camping voyages to forested Watts Island in the lower Bay, 30 or 40 miles from Holland. But Holland, it turns out, lacks the creature comforts of Watts, which is to say high ground.

Holland has a narrow, south-facing isthmus attached to a ham-shaped northern end, but for all its width the ham end is just watery marsh. In the middle of the southern isthmus is a white house with a view west, which must make for spectacular sunsets.

But west-facing lowland in the middle of the Bay will not last long in prevailing westerlies, and eventually the winds will break the island down, as they've done at Poplar Island to the north.

We'll visit there, making the 20-mile haul from Point Lookout by skiff, and watch nature do her work. But someone else will have to buy it.

We've mounted spring camping assaults on beautiful Watts for the last few years. A bunch of guys go in two shallow-draft skiffs, bearing camping, fishing and crabbing gear. Giant sea trout and blues, even huge red drum sometimes invade the point.

But last year an awful thing happened.

We had a beautiful campsite on the south tip--three tents, a fireplace, cookstoves, about eight or 10 coolers to carry back all the fish we ended up not catching, and a huge pile of gear.

The second day we took both boats and headed for the dropoffs where the trout should have been. When we came back the tent flaps were flapping and things didn't look right.

Someone had gotten our food, beer, knives and extra fishing rods. They'd stolen a camera, tacklebox, a bottle of rum, my ditty bag with the car keys in it, all the softshell crabs. They'd run roughshod over our happy little place.

They came by boat, of course, because there's no other way to get to an island like Watts. They had nerve, because nobody knew when we'd be back, even us, and if the crazy West Virginians had caught them in the act, it'd've been blood on the water.

We stood cursing and describing the havoc we'd wreak on people low enough to do a thing like that. Petey and I walked over to my tent.

"Where do you reckon they came from?" he asked.

I pointed across the water, west toward the mainland, and said: